const mysql=require('mysql')

var con=mysql.createConnection({
    host:'192.168.187.144',
    port:3306,
    user:'root',
    password:'ddd',
    database:'mydatabase'
})

var userName=process.argv[2]
var selectSql='select userName,age from users where userName=?'

con.query(selectSql,[userName],(err,result)=>{
    if(err){
        console.log(err)
    }else{
        var userList=result
        for(var i=0;i<userList.length;i++){
            console.log(userList[i]['age'])
        }
    }
})